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EP0284495B1 - Magnetkopf zum Lesen von Spuren mit sehr schmaler Breite und Herstellungverfahren - Google Patents

Magnetkopf zum Lesen von Spuren mit sehr schmaler Breite und Herstellungverfahren Download PDF

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Publication number
EP0284495B1
EP0284495B1 EP88400628A EP88400628A EP0284495B1 EP 0284495 B1 EP0284495 B1 EP 0284495B1 EP 88400628 A EP88400628 A EP 88400628A EP 88400628 A EP88400628 A EP 88400628A EP 0284495 B1 EP0284495 B1 EP 0284495B1
Authority
EP
European Patent Office
Prior art keywords
magnetic
layer
circuit
deposited
track
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP88400628A
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English (en)
French (fr)
Other versions
EP0284495A2 (de
EP0284495A3 (en
Inventor
Jean-Pierre Lazzari
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Original Assignee
Commissariat a lEnergie Atomique CEA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Commissariat a lEnergie Atomique CEA filed Critical Commissariat a lEnergie Atomique CEA
Publication of EP0284495A2 publication Critical patent/EP0284495A2/de
Publication of EP0284495A3 publication Critical patent/EP0284495A3/fr
Application granted granted Critical
Publication of EP0284495B1 publication Critical patent/EP0284495B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
    • G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
    • G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures
    • G11B5/3906—Details related to the use of magnetic thin film layers or to their effects
    • G11B5/3945—Heads comprising more than one sensitive element
    • G11B5/3948—Heads comprising more than one sensitive element the sensitive elements being active read-out elements
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
    • G11B5/332—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using thin films
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
    • G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
    • G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures

Definitions

  • the subject of the present invention is a magnetic reading head for a track of very small width and a method of manufacturing this head.
  • the first solution quickly leads to insurmountable difficulties which arise from the fact that the separation between the read head and the recording layer has to be reduced more and more.
  • Document JP-A-58 70416 describes a process for producing a magnetic head which consists in starting from two massive pieces and in gluing these pieces one on the other with a layer of glass. The air gap is therefore still wide and imprecise.
  • the object of the present invention is precisely to propose a read head specially adapted for reading tracks of very small width.
  • the air gap is defined by a non-magnetic spacer which is obtained by a technique of depositing and etching thin layers. It is therefore of very small width and great precision. It is then easy to complete the assembly with a thin magnetic layer (of the order of a micrometer) which will come from either side of this spacer and which will thus define an air gap whose width of the track to be read.
  • the track can therefore be very narrow (about 1 micrometer).
  • document DE-A-2 205 799 describes a magnetic read head having a magnetic circuit interrupted by two slots in which two magnetoresistive elements are inserted.
  • Document JP-A-592221 describes the integration on the same insulating substrate of a series of electronic circuits and a series of magnetoresistive heads.
  • the present invention incorporates this arrangement consisting in using means sensitive to the magnetic field and inserted into the magnetic circuit.
  • These may for example be magnetoresistors, magnetodiodes, magnetotransistors, and... These elements are mounted in opposition and connected to an integrated circuit diffused in the same substrate which carries the magnetic circuit.
  • FIG. 1 we see a wafer 10 of monocrystalline silicon having an upper face 11 on which electronic circuits 12 are formed, by conventional means in microelectronics.
  • Each circuit includes at least one regulated current generator and a differential amplifier.
  • FIG. 2 shows, in section, the substrate 10, with its circuits 12.
  • An insulating layer 14, for example made of SiO2 is deposited on the assembly to isolate the circuits.
  • Non-magnetic spacers are formed according to a known technique which is illustrated in FIG. 3. For this, an insulating layer 15 is deposited which is etched to reveal vertical walls where the spacers are to be formed (part a) . The thickness of this layer is at least equal to the width of the track to be read. A layer 16 of non-magnetic material is deposited on the assembly (part b).
  • FIG. 4 illustrates the silicon wafer 10 with the integrated circuits 12 and the non-magnetic spacers 20. Naturally, in this figure, the scales are not respected.
  • a layer of material is then deposited on the assembly magnetic with high permeability.
  • the thickness of this layer is equal to the width of the track to be read.
  • This layer is etched to give it the shape illustrated in FIG. 5 to constitute a loop-shaped circuit 30 comprising two pole pieces P1, P2 separated by a spacer 20, and a rear part P3 separated from the pole pieces by two slots F1 and F2 a few micrometers wide.
  • This magnetic circuit is close to the integrated circuit 12.
  • a thin conductive layer 22 is deposited (dashed in FIG. 2) then spacers are produced as illustrated in FIG. 3.
  • a layer of resin is then deposited which is etched according to the shape shown in Figure 5 (the resin remaining outside the hatched area in Figure 5). In the engraved parts, the metal layer is thus released.
  • a thin layer of iron-nickel is deposited on the assembly, by sputtering, which is etched so that only thin strips forming magnetoresistors M1 and M2 remain in the slots F1 and F2. As illustrated in FIG. 7, these fine strips are not in electrical contact with the magnetic circuit.
  • magnetoresistors instead of magnetoresistors, one could insert into slots F1 and F2, magnetodiodes or magnetotransistors made directly on the silicon substrate.
  • a large number of components are thus obtained, each consisting of a magnetic circuit 30 and an integrated circuit 12. These components are cut out and inserted into a flight pad 32, as illustrated in FIG. 9.
  • the assembly is carried out by gluing or by welding with glass.
  • the complete skate includes a flight plan 34 and is in the form of a catamaran. Tracks 36 and 38 pass under the air gap of each magnetic circuit.
  • the face 11, on which the integrated circuit 12 and the magnetic circuit are located, is perpendicular to the flight plane 34 and parallel to the runways 36, 38.
  • the width of the track is equal to the thickness of the magnetic layer forming the circuit.
  • this width can be very small, and of the order of a micron.
  • FIGS. 10 and 11 provide a better understanding of the operation of the read head of the invention, once completed.
  • the arrows in the magnetic circuit show the direction of the magnetization during reading and the arrows in the electrical connections the direction of the current flowing through the magnetoresistors. These are moreover polarized by known means which are not shown (self-polarization, "barber poles", etc.).
  • This polarization is linked to the reading current and to the magnetization, so that the resistance variation is opposite in the two magnetoresistors, that is to say such that the resistance increases in one of the magnetoresistors then that it decreases in the other, for the same variation of the magnetization.
  • FIG. 11 shows the curve of variation of the resistance R of a magnetoresistance as a function of the magnetic field applied.
  • Ho the magnetoresistance has a resistance Ro.
  • ⁇ H there is a relative variation ⁇ R / Ro for one of the magnetoresistors and - ⁇ R / Ro for the other.
  • the current imbalance obtained at the inputs of the differential amplifier is then proportional to 2 ⁇ R / Ro.
  • the value of Ho is chosen to correspond to the maximum slope of the curve (inflection point).

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Magnetic Heads (AREA)
  • Hall/Mr Elements (AREA)

Claims (5)

  1. Magnetlesekopf, umfassend ein Halbleitersubstrat (10), auf dem ein schleifenförmiger Magnetkreis (30) aufgetragen ist, der zwei Polstücke (P1, P2) umfaßt, deren Dicken gleich der Breiten der zu lesenden Magnetspur ist, und die voneinander durch einen Luftspalt getrennt sind, wobei der Magnetkreis durch mindestens einen Zwischenraum unterbrochen ist, in den ein Mittel eingeführt ist, dessen elektrische Eigenschaft auf den Magnetfluß reagiert, wenn unter dem Luftspalt ein auf einer Spur gespeichertes magnetisches Informationselement vorbeiläuft, wobei dieser Kopf dadurch gekennzeichnet ist, daß:
    - er einen nichtmagnetischen Abstandshalter (20) umfaßt, der zunächst auf dem Halbleitersubstrat (10) ausgebildet ist und dessen Höhe mindestens gleich der Breite der Lesespur ist, wobei der Magnetkreis anschließend um den Abstandshalter (20) gebildet wird, die Polteile (P1, P2) auf beide Seite des Abstandhalters (20) kommen, und der Abstandshalter eine Dicke hat, der die Breite des Luftspalts festlegt,
    - der Magnetkreis durch zwei Zwischenräume (F1, F2) unterbrochen ist, die symmetrisch bezüglich einer Ebene des Luftspalts angeordnet sind, wobei die beiden Elemente (M1, M2) mit einer auf das Magnetfeld reagierenden elektrischen Eigenschaft in den beiden Zwischenräumen (F1, F2) in den Magnetkreis eingefügt sind.
  2. Magnetlesekopf nach Anspruch 1, dadurch gekennzeichnet, daß das Halbleitersubstrat einen elektronischen Schaltkreis (12) umfaßt, der in das Substrat integriert ist, wobei dieser elektronische schaltkreis mindestens einen geregelten Stromgenerator (G) und einen im Gegentakt geschalteten Differenzverstärker (A) mit zwei Eingängen umfaßt, die mit den beiden Elementen (M1, M2) verbunden sind, wobei die beiden Elemente (M1, M2) einenader entgegengesetzt mit den Eingängen des Differenzverstärkers (A) verbunden sind, und die beiden Elemente (M1, M2) so polarisiert sind, daß sie bei einer Änderung des magnetischen Flusses gegenläufig einer Veränderunge ihrer elektrischen Eigenschaften ausgesetzt sind, wobei der Ausgang des Differenzverstärkers (A) das Lesesignal des Kopfes liefert.
  3. Verfahren zur Herstellung eines Lesekopfes nach Anspruch 1, dadurch gekennzeichnet, daß auf einer ersten Seite (11) eines Halbleitersubstrats (10) integrierte Schaltkreise (12) hergestellt werden, die je einen Stromgenerator (G) und einen Differenzverstärker (A) umfassen,
    - auf dieser Seite (11) des Substrats eine Isolierschicht (14) aufgetragen wird,
    - eine Isolierschicht (15) von einer Dicke aufgetragen wird, die mindestens gleich der Breite der Lesespur ist, diese Schicht (15) graviert wird, um vertikale Wände dort entstehen zu lassen, wo die nichtmagnetischen Abstandshalter ausgebildet werden sollen, auf das Ganze eine Schicht (16) nicht magnetischen Materials aufgetragen wird, alle Horizontalteile der Schicht (16) nicht magnetischen Materials entfernt werden, um nur die Vertikalteile (18) der Schicht (16) stehen zu lassen, und die Reste der Isolierschicht (15) entfernt werden, was zu einer gleichen Anzahl nicht magnetischer Abstandshalter (20) wie integrierten Schaltkreisen (12) führt, wobei die Höhe jedes Abstandhalters größer als die Breite der zu lesenden Spur ist,
    - ebensoviele Magnetkreise (30) wie integrierte Schaltkreise (12) hergestellt werden, wobei jeder Schaltkreis die Form einer Schleife (B1, B2, B3) hat und den Abstandshalter (20) einzwängt, der den Luftspalt festlegt, wobei jede Schleife zwei Zwischenräume (F1, F2) aufweist, die symmetrisch zur Ebene des Luftspalts sind,
    - in jeden der Zwischenräume (F1, F2) zwei Elemente (M1, M2) angeordnet werden, die eine auf das Magnetfeld reagierende Eigenschaft haben,
    - die beiden Elemente (M1, M2) mit dem zugeordneten integrierten Schaltkreis (12) verbunden werden,
    - die verschiedenen, erhaltenen Bauteile auseinandergeschnitten werden.
  4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, daß zum Herstellen der Magnetkreise auf die Isolierschicht (14) eine Schicht magnetischen Materials mit hoher Permeabilität aufgetragen wird, deren Dicke gleich derjenigen der Lesespur ist, und daß diese Schicht graviert wird, um sie schleifenförmig zu formen.
  5. Verfahren nach Anspruch 3, dadurch geKennzeichnet, daß zum Herstellen der Magnetkreise auf die Isolierschicht (14) eine Leitungsschicht (22) auftragen wird, auf diese Leitungsschicht eine Harzschicht aufgetragen wird, diese Harzschicht in den Bereichen graviert wird, die dem späteren Magnetkreis (30) entsprechen, elektrolytisch eine Magnetschicht hoher Permeabilität auf der Leitungsschicht solange zum Wachsen gebracht wird, bis eine Dicke erreicht ist, die der Breite der Lesespur gleicht, und die Reste des Harzes sowie die Leitungsschicht (22) dort entfernt werden, wo sie außerhalb des Magnetkreises erscheint.
EP88400628A 1987-03-19 1988-03-16 Magnetkopf zum Lesen von Spuren mit sehr schmaler Breite und Herstellungverfahren Expired - Lifetime EP0284495B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8703821A FR2612676B1 (fr) 1987-03-19 1987-03-19 Tete magnetique de lecture pour piste de tres faible largeur et procede de fabrication
FR8703821 1987-03-19

Publications (3)

Publication Number Publication Date
EP0284495A2 EP0284495A2 (de) 1988-09-28
EP0284495A3 EP0284495A3 (en) 1990-10-31
EP0284495B1 true EP0284495B1 (de) 1993-09-08

Family

ID=9349203

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88400628A Expired - Lifetime EP0284495B1 (de) 1987-03-19 1988-03-16 Magnetkopf zum Lesen von Spuren mit sehr schmaler Breite und Herstellungverfahren

Country Status (6)

Country Link
US (1) US4901177A (de)
EP (1) EP0284495B1 (de)
JP (1) JPS63255809A (de)
DE (1) DE3883819T2 (de)
FR (1) FR2612676B1 (de)
IE (1) IE63080B1 (de)

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FR2645314B1 (fr) * 1989-03-29 1991-05-31 Commissariat Energie Atomique Tete magnetique a magnetoresistance pour enregistrement longitudinal et procede de realisation d'une telle tete
FR2645315B1 (fr) * 1989-03-29 1991-05-31 Commissariat Energie Atomique Tete magnetique de lecture a magnetoresistance pour enregistrement perpendiculaire et procede de realisation d'une telle tete
FR2656454B1 (fr) * 1989-12-22 1995-07-21 Thomson Csf Tete de lecture multipiste.
FR2658647B1 (fr) * 1990-02-21 1992-04-30 Commissariat Energie Atomique Tete magnetique horizontale a effet hall et son procede de realisation.
US5508868A (en) * 1993-01-25 1996-04-16 Read-Rite Corporation Dual element magnetoresistive sensing head having in-gap flux guide and flux closure piece with particular connection of magnetoresistive sensing elements to differential amplifier
FR2709855B1 (fr) * 1993-09-06 1995-10-20 Commissariat Energie Atomique Tête magnétique de lecture et d'écriture à élément magnétorésistant compensé en écriture.
CN1067788C (zh) * 1994-03-07 2001-06-27 国际商业机器公司 制造磁传感器的方法和制造磁盘存储系统的方法
JP2970455B2 (ja) * 1994-03-14 1999-11-02 株式会社デンソー 磁気抵抗素子の製造方法およびその磁場処理装置
JPH07270507A (ja) * 1994-03-28 1995-10-20 Sony Corp 地磁気方位センサ
US6091581A (en) * 1994-08-26 2000-07-18 Aiwa Co., Ltd. Thin film magnetic head including a separately deposited diamond-like carbon gap structure and magnetic control wells
US5563754A (en) * 1994-08-26 1996-10-08 Aiwa Research And Development, Inc. Thin film magnetic head including a durable wear layer and gap structure
US5801909A (en) * 1994-08-26 1998-09-01 Aiwa Research And Development, Inc. Thin film magnetic head including durable wear layer and non-magnetic gap structures
US5909346A (en) * 1994-08-26 1999-06-01 Aiwa Research & Development, Inc. Thin magnetic film including multiple geometry gap structures on a common substrate
US5544774A (en) * 1994-08-26 1996-08-13 Aiwa Research And Development, Inc. Method of eliminating pole recession in a thin film magnetic head
US5748417A (en) * 1994-08-26 1998-05-05 Aiwa Research And Development, Inc. Thin film magnetic head including layered magnetic side poles
US5673474A (en) * 1994-08-26 1997-10-07 Aiwa Research And Development, Inc. Method of fabricating a thin film magnetic head including layered magnetic side poles
JPH08171712A (ja) * 1994-08-26 1996-07-02 Aiwa Co Ltd 側面露出型薄膜磁気ヘッド並びにその製造方法
US5754377A (en) * 1994-08-26 1998-05-19 Aiwa Research And Development, Inc. Thin film magnetic head including an elevated gap structure
US5490028A (en) * 1994-08-26 1996-02-06 Aiwa Research And Development, Inc. Thin film magnetic head including an integral layered shield structure
US5587857A (en) * 1994-10-18 1996-12-24 International Business Machines Corporation Silicon chip with an integrated magnetoresistive head mounted on a slider
US5621594A (en) * 1995-02-17 1997-04-15 Aiwa Research And Development, Inc. Electroplated thin film conductor coil assembly
US6069015A (en) * 1996-05-20 2000-05-30 Aiwa Research And Development, Inc. Method of fabricating thin film magnetic head including durable wear layer and non-magnetic gap structure
US5768070A (en) * 1997-05-14 1998-06-16 International Business Machines Corporation Horizontal thin film write, MR read head
DE69725123D1 (de) * 1997-07-04 2003-10-30 St Microelectronics Srl Ein elektromagnetischer Kopf mit magnetoresistiven Mitteln verbunden mit einem Magnetkern
US8953284B1 (en) 2013-11-20 2015-02-10 HGST Netherlands B.V. Multi-read sensor having a narrow read gap structure

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JPS5931770B2 (ja) * 1978-09-19 1984-08-04 三菱電機株式会社 磁気ヘツドのコアの製造方法
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JPS5870416A (ja) * 1981-10-20 1983-04-26 Matsushita Electric Ind Co Ltd 磁気ヘツドの製造方法
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JP2613876B2 (ja) * 1986-11-28 1997-05-28 日本電気株式会社 薄膜磁気ヘッドの製造方法

Also Published As

Publication number Publication date
IE880795L (en) 1988-09-19
DE3883819D1 (de) 1993-10-14
IE63080B1 (en) 1995-03-22
FR2612676B1 (fr) 1993-12-31
US4901177A (en) 1990-02-13
JPS63255809A (ja) 1988-10-24
DE3883819T2 (de) 1994-03-17
FR2612676A1 (fr) 1988-09-23
EP0284495A2 (de) 1988-09-28
EP0284495A3 (en) 1990-10-31

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